Proxy re-encryption (PRE) is a system which allows decryption rights for ciphertexts to be delegated to third parties without decrypting the ciphertexts. Non-Patent Literature 1 discusses an identity-based PRE (IBPRE) scheme. Non-Patent Literature 2 discusses an attribute-based PRE (ABPRE) scheme. According to the PRE scheme discussed in Non-Patent Literature 2, only attributes consisting of AND and negative elements can be specified for ciphertexts.
Patent Literature 1 discusses functional encryption (FE).